The HOTP Toolkit package contains tools that are useful when deploying the one-time password HOTP technology. It contains a shared library, a command-line tool to generate and validate one-time passwords, and a PAM module (pam_hotp) to make system login or SSH use HOTP one-time passwords for authentication.
The OATH Toolkit makes it easy to build one-time password authentication systems. It contains shared libraries, commandline tools, and a PAM module. Supported technologies include the event-based HOTP algorithm (RFC4226) and the time-based TOTP algorithm (RFC6238). OATH stands for Open AuTHentication, which is the organization which specifies the algorithms. For managing secret key files, the Portable Symmetric Key Container (PSKC) format described in RFC6030 is supported.
pysrp is a Python module that provides an implementation of the Secure Remote Password protocol (SRP), a cryptographically strong authentication protocol for password-based, mutual authentication over an insecure network connection. Unlike other common challenge-response autentication protocols, such as Kerberos and SSL, SRP does not rely on an external infrastructure of trusted key servers or certificate management. Instead, SRP server applications use verification keys derived from each user's password to determine the authenticity of a network connection.